A number of cases have been reported in which the caudal, dorsal portion of the fifth lumbar vertebral body has become greatly worn or has collapsed after prosthesis implantation. The risk of collapse arises if the vertebra has been worn away in the dorsal area and the remaining dorsal lip breaks off or too much is removed. This finding, which is part of the inventive achievement, leads to the object of making available an intervertebral prosthesis which in such a case reduces the risk of collapse. This is achieved by using the corrective cover plate specified in claim 1.
The prior art also includes (PCT/EP02/03132=WO 02/080818) a corrective plate whose internal engaging surfaces, compared to normal prostheses, are offset in the AP direction in relation to the contact surface. This affords the possibility of positioning the joint center of a prosthesis elsewhere than is the case in standard prostheses.